因此,我有一个Tkinter GUI,其中有两个简单的选项,即开始和停止按钮。我已经定义了GUI布局:

from Tkinter import *

def scanning():
    while True:
        print "hello"

root = Tk()
root.title("Title")
root.geometry("500x500")

app = Frame(root)
app.grid()

在这里,“开始”按钮将运行无限循环扫描,而“停止”按钮在按下时应会中断:
start = Button(app, text="Start Scan",command=scanning)
stop = Button(app, text="Stop",command="break")

start.grid()
stop.grid()

但是,当我按下“开始”按钮时,它总是被按下(假设由于无限循环)。但是,我无法单击停止按钮来打破while循环。

最佳答案

您不能在Tkinter事件循环所处的同一线程中启动while True:循环。这样做将阻塞Tkinter的循环并导致程序卡住。

对于一个简单的解决方案,您可以使用 Tk.after 每隔一秒左右在后台运行一个进程。下面是一个脚本来演示:

from Tkinter import *

running = True  # Global flag

def scanning():
    if running:  # Only do this if the Stop button has not been clicked
        print "hello"

    # After 1 second, call scanning again (create a recursive loop)
    root.after(1000, scanning)

def start():
    """Enable scanning by setting the global flag to True."""
    global running
    running = True

def stop():
    """Stop scanning by setting the global flag to False."""
    global running
    running = False

root = Tk()
root.title("Title")
root.geometry("500x500")

app = Frame(root)
app.grid()

start = Button(app, text="Start Scan", command=start)
stop = Button(app, text="Stop", command=stop)

start.grid()
stop.grid()

root.after(1000, scanning)  # After 1 second, call scanning
root.mainloop()

当然,您可能需要将此代码重构为一个类,并让running作为其属性。同样,如果您的程序变得很复杂,那么研究Python的 threading module将会是有益的,这样您的scanning函数可以在单独的线程中执行。

10-08 05:38
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